By Amy Woolfolk

MISSISSIPPI STATE -- Temperatures may be cooling, but yellow jacket season is just heating up before winter sends them packing.

"Yellow jackets are more noticeable now because their eggs hatched in the summer, producing high populations by fall," said Dr. James Jarratt, extension entomologist at Mississippi State University.

Jarratt said the best protection against yellow jacket stings is awareness. Because they generally nest in the ground, they may go unnoticed until it's too late to avoid them. They also build nests in storage buildings, garages and boats.

Yellow jackets become very aggressive and defensive when someone threatens their territory. Jarratt urged anyone participating in outdoor activities such as mowing, hiking and picnicking to watch carefully for yellow jackets.

The stinging predators feed mostly on other insects, but sweet, syrup-like substances often leaking from hummingbird feeders and vine-ripe fruits attract yellow jackets.

"Homeowners need to make sure bird feeders do not leak, and they should remove ripened fruits such as muscadines from the vines before they begin to crack and leak juices," Jarratt said.

Yellow jackets often cause problems around schools and parks where people discard sodas and candy in open trash cans, Jarratt said. The best way to keep yellow jackets away from these places is to use covered trash cans and try to keep the area clean.

There are no sprays available to combat individual yellow jackets, Jarratt said. But treatments can be directly applied to the insects' nest. These may be liquids or sprays, but Jarratt warned against using gasoline on yellow jacket nests.

"Many people think gasoline is the answer to anything in the ground, but it's not," Jarratt said. "There are approved substances to treat yellow jacket nests, but gasoline is not one of them."

The most important thing in getting rid of yellow jackets is to determine the exact entrance to the nest. Then use an approved insecticide to flood the entrance to the nest, Jarratt said.

Jarratt said the safest time to apply any treatment is late in the afternoon, just before dark. At this time of day, yellow jackets are much less active, making it safer for the applicator.

Local extension offices have a list of approved substances for treating yellow jackets. Be sure to follow all label instructions.